Page 485 - Atlas of Histology with Functional Correlations

slide preparations. At a higher magnification, the outlines of flattened cells and

eleidin droplets in this layer are occasionally seen.

Located below the stratum lucidum (2) is the stratum granulosum (3, 11),
in which the cells are filled with dark-staining keratohyalin granules (3).
Directly under the stratum granulosum (3, 11) is the thick stratum spinosum (4,
12) composed of several layers of polyhedral cells. These cells are connected to

each other by spinous processes or intercellular bridges that represent the
desmosomes (macula adherens).

The deepest cell layer in the skin is the columnar or cuboidal stratum basale
(5, 13) that rests on the basement membrane (6, 15). Mitotic activity and the

brown melanin pigment (5, 13) are seen in the deeper layers of the stratum
spinosum (4, 12) and stratum basale (5, 13).

The excretory duct of a sweat gland (10) located deep in the dermis
penetrates the epidermis, loses its epithelial wall, and spirals through the
epidermal cell layers (1 to 5) to the skin surface as small channels with a thin

lining.

Dermal papillae (7) are prominent in thick skin, where they indent the
inferior surface of the epidermis. Some dermal papillae (7) may contain tactile or
sensory Meissner corpuscles (14) and capillary loops (16).

FIGURE 12.8 ■ Thick skin of the palm, superficial cell layers, and melanin
pigment. Stain: hematoxylin and eosin. Medium magnification.

FIGURE 12.9 | Thick Skin: Epidermis and

Superficial Cell Layers

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